Investigation of the wet-etching mechanism of Ga-polar AlGaN/GaN micro-pillars

The wet-etching mechanism of Ga-polar AlGaN/GaN micro-pillars is analyzed in this work. By using solutions of KOH in ethylene glycol (KE), we discover the difference in wet-etching processes with and without an AlGaN layer. In the Ga-polar micro-pillar GaN-based nano-wire, a micro-pillar with {1−100} facet and a pyramid with a {11−212} facet are realized by accurately controlling the wet-etching rate and time, respectively. Schematic drawings are established to explain the dissimilarity of these two structures. Our research attempts to fabricate lager scale nano-wires and quasi-polarity substrates. Support information of large scare SEM images of different micro-array after ICP etching [Display omitted] •The wet-etching mechanism of Ga-polar AlGaN/GaN micro-pillars is proposed by using solutions of KOH in ethylene glycol (KE).•Different wet-etching mechanisms are discovered on the Ga-polar AlGaN/GaN micro-pillars and GaN micro-pillars.•Micro-pillar with {1−100} facet and pyramid with {11−212} facet are realized by accurately controlling wet-etching rate and time.